Thunderstorm Wind — Nuckolls, Nebraska

2017-06-20 · near Superior, Nuckolls, Nebraska

Event narrative

Wind gusts were estimated to around 75 MPH. Tree limbs of 6 to 10 inches in diameter were downed, and several streets closed due to trees across them. Power was out for much of the town for several hours. A couple vehicles were damaged by falling tree limbs. A 40 foot section of a roof was blown off of the local lumberyard and an awning was damaged at another business. At least 9 irrigation pivots were damaged south of town. Most of the damage focused between 8th Street and the Republican River.

Wider weather episode

Although just one lone strong-to-severe thunderstorm tracked across far southern portions of South Central Nebraska on this Tuesday evening, it wreaked havoc on one particular community: Superior in Nuckolls County. Estimated 75 MPH winds struck primarily southern portions of town around 10 p.m. CDT, causing extensive damage to trees and power lines and ripping a 40-foot section of roof from a lumberyard building, among other damages. Although severe wind was the main story in Superior, hail up to golf ball size also fell. While the immediate Superior area bore the brunt of storm headlines, hail ranging from half dollar to ping pong ball size fell a bit farther west in the Riverton and Inavale areas, with some wind damage also reported near Inavale.

This storm initially flared up around 7:30 p.m. CDT over northern Harlan County and quickly exhibited severe weather potential per radar data, although no ground-truth reports were received early in its life cycle. Between 8-10 p.m. CDT, it tracked east-southeast through portions of Franklin, Webster and Nuckolls counties, fluctuating in intensity and occasionally showing supercell characteristics. Around 10 p.m. CDT it slammed into Superior, with radar data suggesting evidence of a collapsing core and the resultant surge of damaging winds. Shortly thereafter, it slipped south of the state line into Kansas and weakened below severe thresholds within 30 minutes.

In the mid-upper levels, South Central Nebraska was under a pronounced northwesterly flow regime, situated northeast of a large-scale ridge centered over the Desert Southwest. Although forcing aloft was fairly nebulous, this severe storm developed in the vicinity of a warm front taking shape near the Nebraska-Kansas border, marked in part by surface dewpoints gradually increasing into the upper 50-lower 60s F range over the course of the evening. This increasing low level moisture, in combination with afternoon temperatures climbing well into the 90s, contributed to a mesoscale environment fairly supportive of severe weather, featuring 1000-2000 J/kg mixed-CAPE and effective deep layer wind shear around 40 knots.

View location on OpenStreetMap → (40.0258, -98.0665)

Source: NOAA Storm Events Database, event_id 703888. Narrative written by the NWS forecast office that issued the report.